The present invention relates generally to high density connectors and, more particularly, to high density connectors that are used to connect two printed circuit boards together in orthogonal and other arrangements.
High-density interconnect systems are used in numerous data communication applications, one such application being in network servers and routers. In many of these applications, the interconnect systems include male and female connectors that are mounted to different circuit boards, such as in the manner of conventional right-angle connectors, in which the two circuit boards are oriented at 90xc2x0 with respect to each other, so that two edges of the circuit boards abut each other. Servers and routers require that the two circuit boards be joined together. In instances where the device system requires the use of multiple pairs of connectors to join the two circuit boards together, problems may occur when one or more of the connectors are misaligned. One, or more, of the connectors on one of the two circuit boards may be misaligned with their corresponding opposing connector on the other of the two circuit boards.
These connectors are not able to move, or xe2x80x9cflexxe2x80x9d either up or down, side to side or in other directions, which can lead to serious system complications in that misalignment renders the connecting together of the two circuit boards very difficult, if not impossible. Also, if one connector is misaligned with its opposing mating connector, the mating portions of the connectors"" terminals may not mate, thereby deleteriously affecting the performance of the network or router.
High-density connectors typically use pin and box terminal or blade to blade terminal mating arrangements. With these type structures, it is necessary to utilize terminal mating, or contact, portions with reliable lead-ins and alignment features in order to prevent the bending of the terminal contact portions. Bent terminals are a problem in the field of high-density, board to board connectors.
A need therefore exists for a high-density interconnection system that has the capability to move in one and/or two different directions so as to tolerate potential misalignment between opposing circuit board connectors.
A need further exists for a high-density interconnection system including connector assemblies in which the terminal mating portions of the opposing connectors are properly aligned with each other for better mating and have a terminal structure that promotes reliable contact between the opposing terminals.
The present invention is directed to an improved interconnection assembly that overcomes the aforementioned disadvantages.
Accordingly, it is a general object of the present invention to provide an interconnection system that utilizes a pair of connectors, each mounted near an edge of a respective circuit board and each oriented thereon so that the circuit boards may be spaced near each other and the connector mounted on one of the circuit boards are able to flex a preselected amount, thereby giving to one set of connectors, a measure of flexibility so as to tolerate misalignment between sets of mating connectors.
Another object of the present invention is to provide an interconnection system that utilizes plug and receptacle connectors, the terminals of one of the two connectors being held in place within their associated housings and terminals of the other connector being movable within their associated housing to a preselected extent so as to flex in at least one, and preferably, two different and relevant directions so as to overcome the aforementioned misalignment problems.
A further object of the present invention is to provide a connector assembly with the aforementioned flexure characteristics wherein at least one of the connectors is formed from a plurality of individual subassemblies in the form of wafers support sets of conductive signal and ground terminals and which are arranged in an alternating fashion with respect to the connector terminals such that every grounding member wafer is flanked on opposing sides thereof by an associated signal terminal wafer.
Yet another object of the present invention is to provide a flexible connector for use in the aforementioned connector assembly, wherein the connector includes a plurality of connector wafers assembled together to define a connector body, or housing unit, in the form of a block of wafers, each connector wafer including a set of conductive terminals supported thereby, each of the terminals having a tail portion for connecting to one of the two circuit boards, a body portion supported by the connector wafer, a mating portion extending from one edge of the connector wafer for mating with an opposing terminal of an opposing connector, the mating and body portions, the terminals being interconnected by intervening flexural portions of variable thickness that permits flexing of the terminal mating portions in both vertical and horizontal directions.
Another object of the present invention is to provide a circuit board connector for joining together two circuit boards, wherein the connector has a mating end positioned near an edge of a first circuit board, the mating end having flexural properties that permit the mating end to move in a limited amount in two different directions, preferably orthogonal to each other, the connector having a body portion that supports a plurality of conductive terminals, the terminals having contact or mating free ends that are fixed in place within the connector housing body at the point where their contact portions project from the connector housing body, and which are enclosed by a hollow shroud that encircles the contact free ends, the shroud being supported by supports which cross and link together groups of the terminal contact portions within the shroud so that the shroud and the terminal contact portions can move together as a single unit in at least two different, orthogonal directions, while keeping the terminal contact portions in a mating orientation without relative movement between the contact portions.
Still another object of the present invention is to provide an outer cover assembly that engages the mating end of the flexural connector, the cover assembly including a clamp member that engages the block of connector wafers and serves to keep them together in a block configuration and a floating shroud member that movably engages the clamp member and provides a protective outer cover around the perimeter of the terminal mating portions, the terminal mating portions being partially held in their orientation by elongated dielectric support rails that are received within the cover portion and abut against at least one interior shoulder of the cover portion and which may be held in place thereagainst by one or more key members that are applied to the exterior of the cover and which penetrate the cover to engage and press against the support rails.
Yet still another object of the present invention is to provide a high-density connector for board to board connections in single-ended signal applications, wherein the connector includes a plurality of terminal assemblies assembled together into a single unit, each terminal assembly including a plurality of arrays of conductive terminals, the terminal arrays including at least two signal terminal arrays and an associated single array of ground member terminals, the terminal assemblies being supported on insulative blocks that are held together, the signal terminal and ground member assemblies each including conductive elements with contact portions projecting from a common first side of the respective signal terminal blocks, the ground member having a plurality of conductive tabs formed therein that extend out from the plane of the grounding member in two different directions into contact with selected ground reference terminals of the signal terminal sets, the ground terminals and ground reference terminals flanking individual signal terminals.
Still another object of the present invention is to provide a high-speed, high-density connector assembly that uses a plurality of contact pins projecting forwardly from a connector body, the contact pins being capable of flexural movement and being arranged in a plurality of vertical, linear arrays, each array being separated from an adjacent array by an intervening dielectric spacer element that extends crosswise to the direction of the contact pins and along flexing portions of the contact pins, the spacer element preventing unintentional shorting of the terminals during flexing of the connector and providing a dielectric interface therebetween.
Yet a further object of the present invention is to provide a high density interconnection system that utilizes plug and receptacle-style connectors having terminals with structures that prevent the excessive bending of the terminals when opposing connector components are mated together.
Another object of the present invention is to provide a high-density connector that has a plurality of conductive terminals supported on an insulative housing and wherein the terminals are separated into distinct sets of signal and ground terminals, the ground terminals including double thickness, flat contact blades that project forwardly of the connector body and the signal terminals having contact portion with general L-shapes, the signal terminal being arranged on opposite sides of the ground blades in a cruciform pattern.
A still further object of the present invention is to provide a connector for mating with the high-density connector described above, wherein the signal terminal of this connector include contact portions which are also L-shaped and which include a pair of contact arms that extend in different planes from an L-shaped body portion of the terminals to provide a redundant mating contact with an opposing connector.
Yet another object of the present invention is to provide a high-density, high-speed connector structure which utilizes a double ground to provide both ground reference to signal terminals and isolation between rows of signal terminals.
The present invention accomplishes the aforementioned and other objects by way of its novel and unique structure.
In one principal aspect of the present invention, a flexural high density connector assembly is provided whose primary purpose is to connect together two orthogonally-oriented circuit boards. The assembly includes a plug connector mounted to a first circuit board and a receptacle connector mounted to a second circuit board. One of the connectors, preferably the receptacle connector, includes a structure that permits it to flex in the mating region thereof in both the horizontal and vertical (xe2x80x9cXxe2x80x9d and xe2x80x9cYxe2x80x9d) directions. This flexure permits the connector assembly to be utilized in instances where either of the connectors may be misaligned in their mounting positions on their respective circuit boards.
In this regard, and in another principal aspect of the present invention, the receptacle connector includes a plurality of subassemblies, or xe2x80x9ctri-wafers,xe2x80x9d which are assembled together from three different parts and which include two single-ended signal terminal sets flanking a ground terminal set. The terminals sets are supported on dielectric housings and have tail portions extending from one side of the housing which mate with a circuit board, contact portions that extend from another side of the housing for mating with terminals of an opposing connector and body portions interconnecting the contact and tail portions together and which are supported by the housings.
Flexural portions are formed in the terminals and are interposed between the terminal contact and body portions. The flexural portions are located outside of the connector housings as are the terminal contact portions, and they include a center portion of approximately the same width as the terminal body portions, but flanked by two thin neck portions, or flex arms that deflect when needed, while the thicker center portion provides strength and electrical performance to the terminal flexural portions. The terminals may further be aligned together by elongated, vertical support members, preferably molded in place thereon of a dielectric material. These support members preferably take the form of elongated bars that maintain each set or array of terminals supported by a wafer in a fixed spacing and alignment. The support bars fix the terminal contact portions at a pont spaced from a common face of the wafer. The support bars at this point are fixed to a moveable housing, preferably taking the form of a shroud member that thus both the terminal mating portions and the shroud will move as a single unit with respect to the common face of the supporting wafer.
The contact portions of the connector terminals are arranged in linear arrays, and preferably vertical linear arrays. The invention also includes a plurality of dielectric spacers that are interposed between adjacent terminal arrays and these spacer elements take the form, in the preferred embodiment of a planar comb that extends transverse to the axes of the contact portions of the terminals. The spacer element is held in place between adjacent terminal arrays by lugs formed wit the spacer which project into the space between two of the terminals. In this manner, the spacer element will also move up or down or side to side with the terminal contact portions during mating engagement. The spacer element may include means for engaging one of the terminal arrays between which it is interposed, or it may be affixed to the support bars. The dielectric material used in the spacer element affects the electrical affinity of terminal between which it is interposed, and thereby permits a measure of tuning the electrical performance of the terminals, such as impedance, in their flexing portions.
In order to provide effective shielding to the connector of the assembly and in a second principal aspect of the present invention, the inner portion of each connector terminal assembly includes a grounding shield which may be held in a plastic or dielectric frame and in which a plurality of tabs may be stamped. These tabs extend sideways from the plane of the shield and are intended to contact distinct ground terminals that are disposed in the signal terminal sets. The signal terminal sets may be stamped and formed from a conductive material and preferably have an exterior insulative frame, or housing, molded over the body portions thereof. Cavities are preferably formed in the frames into which the grounding shield tabs project to contact their associated grounding terminals of the adjoining signal terminal sets or arrays.
In another principal aspect of the present invention, the signal and ground terminal assemblies and frames are assembled together to form xe2x80x9ctri-wafersxe2x80x9d. These distinct tri-wafers may be separately removed from the entire connector in order to facilitate the removal and replacement thereof. Each such signal and/or ground terminal assembly is supported on a single wafer in one embodiment of the invention and are held together as a unit to form the aforementioned tri-wafer. The center wafer of each such tri-wafer supports a ground terminal assembly and the ground tabs formed therein make contact with terminals of the signal terminal sets that are intended to carry ground signals in the adjoining signal terminal assemblies in a pattern so that each signal terminal in the array of signal terminals will have a ground terminal flanking it in both horizontal and vertical directions.
In yet another aspect of the present invention, a cover assembly is provided that partially encloses the receptacle connector contact portions. This cover assembly includes a clamp member that engages the tri-wafers as a single block, and which forms a support for a shroud member of the cover assembly. The shroud member is provided to form a housing around the receptacle connector terminal mating portions and includes an inner shoulder against which the terminal flexural portion supports, or support bars, abut in contact.
One or more keys, or clips, may also be provided which extend through the shroud in order to press the terminal support bars against the inner shoulders of the shroud. These keys engage the shroud and press against the support bars in a manner to maintain them in contact with an interior shoulder formed in the shroud. The keys preferably have a plurality of fingers or arms that press on the terminal supports, with one finger pressing on the end of a single terminal support bar. Two such keys are utilized to hold the support bars and their accompanying terminals in a fixed position within the shroud and spaced apart from the connector wafer blocks. These keys hold the support bars firmly in place. The shroud may have lead-in surfaces or portions formed therewith that direct either an opposing connector unto the connector or directs the shroud over the mating end of the opposing connector. In this manner, the shroud is permitted to float in its mounting on the clamp member and move as one piece with the terminal flexural portions.
In another embodiment of the invention, the shroud member is slotted in order to align the terminal assemblies of the receptacle connector and in order to space them apart a desired spacing. These slots include cavities which receive engagement keys. The keys extend into the cavities and into the slots to bear against and exert a retention pressure on the terminal assembly support bars.
In still another principal aspect of the present invention, power terminals may be provided in both the plug and receptacle connectors in order to conduct power between the two circuit boards. The power terminals are larger and wider in size to carry an effective amount of current through the connector. The power terminals also include flexural portions that are interposed between their body and contact portions.
In yet another principal aspect of the present invention and as exemplified by another embodiment of the invention, the wafers includes terminal assemblies that include distinct signal and ground terminal sets. The ground terminals include pairs of flat contact blades that are aligned together in abutting contact to form a column of ground contacts blades of double width, when the connector wafers are arranged vertically. The signal terminals are arranged in sets on opposite sides of the ground terminal blades and the signal terminals have a general L-shape. One of the connectors has solid L-shaped contacts that are arranged in sets of two pairs of contacts to form a cruciform pattern. The other of the connectors has bifurcated, or dual beam, L-shaped contacts in which a pair of contact arms (that lie and extend in two different planes) project from a terminal body in a manner so as to mate with the contact portions of the solid L-shaped contacts and to provide redundancy between the opposing contacts.
In another aspect of the present invention, the connector assemblies include a pair of mating connectors and each connector includes a housing that receives and holds together a plurality of individual connector components, preferably in the form of an assembly of wafers. Each wafer may include first and second sets of signal terminals and first and second sets of ground terminals. The signal and ground terminals all include conductive contact portions, tail portions and body portions that interconnect the contact and tail portions together, and the first and second sets of signal terminals being at least partially enclosed by an insulative covering. These two insulative coverings and the first and second sets of ground terminals cooperatively form a single terminal assembly wafer, with all of the terminal assembly wafers in the receptacle connector being of the same type.
The first and second sets of signal and ground terminals have flat blade portions that are arranged within each connector component so that the first and second sets of ground terminals preferably abut each other and extend in a vertical line down the center of the wafer. The first and second sets of signal terminals lie on opposite sides of, or xe2x80x9cflankxe2x80x9d, the first and second sets of ground terminals and the insulative coverings of the first and second signal terminal sets prevent unintended shorting from occurring between the signal and ground terminals. The first and second sets of signal terminals are further arranged so that one pair of first signal terminals and one pair of second signal terminals are disposed on opposite sides of one of the contact portions of the first and second sets of ground terminals. In this arrangement, the L-shaped signal terminal contact portions extend in directions that are both parallel and perpendicular to the ground terminal flat blade portions and the first and second signal terminal pairs form a cruciform pattern around their associated ground blade when viewed from a contact end thereof.
The signal terminal contact portions in this pattern are preferably spaced closer to their associated ground contact blades than they are to the signal terminal contact portion of signal terminals of an adjacent terminal assembly, thereby encouraging signal to ground coupling and discouraging signal to signal coupling from occurring during operation of the connector. In one embodiment, the terminal assemblies are spaced apart from each other and are maintained in such a spacing by both a retainer and the shroud in order to encourage signal to ground capacitive coupling and discourage signal to signal capacitive coupling of adjacent terminal assemblies.